Protection devices, i.e., protective equipment, are known, usable during the performance of sports activities for the purpose of protecting one or more parts of the body from potentially dangerous knocks and contacts.
Among this type of device are shin guards, mainly used in soccer or similar sports (5-a-side soccer, 7-a-side soccer and the like).
Shin guards are rigid or semi-rigid supports, shaped so as to cover the front portion of the leg and the function of which is to cushion the effect of any direct blows on the user's shins.
Other protection devices wearable during the performance of sports activities are elbow guards, knee guards and other similar equipment used to protect one or more parts of the body against contacts potentially dangerous for the safety of the athlete.
The need is known to monitor the physical conditions of the athletes, both as regards individual performances, and as regards team performance.
Furthermore, training methods and monitoring techniques have been developed, both as regards training and the match, which require the processing of data and information to be acquired during the carrying out of the activities.
For example, modern “match analysis” techniques involve a study phase of the data on individual and collective performance such as, e.g., the position of the players on the field, the distances between them and their changes in real time.
This information is acquired during activities by means of various different acquisition systems (from images, videos, metabolic parameters, blood tests, etc.).
In this context, there is an increasingly greater need to obtain data sampled directly on the individual athletes and to be analysed both in real time and in a subsequent post-processing.
The known techniques in fact provide results often based on data obtained indirectly from images, videos or other parameters, bringing with them inevitable errors of accuracy which are propagated in the processing operations subsequent to sampling, until the goodness of the end results is affected.
The processing of the detected data in fact is an aspect of far from secondary importance precisely because it affects the precision of the end results.
The known processing methods are based on techniques and algorithms based on mathematical models describing the athlete's movements.
Among the known techniques, mention is made of the “Zero Velocity Update Techniques” (ZUPT), the models of which describe the gesture of the walk/run identifying a number of points of interest to be associated with particular conditions (zero velocity).
The drawback of these techniques stems from the fact that they are not particularly suitable for use in sports activities such as soccer and the like.
In fact, the gestures of the athletes who practise these sports activities are unexpected and sudden, unlike a walk or linear run.
By applying the ZUPT techniques to soccer activities or the like, the statistical errors would not be negligible and their propagation would considerably affect the end result.